The uterine lining, or endometrium, is the internal layer of the uterus which thickens and gets filled with blood vessels in preparation to receive a fertilized egg. If this does not happen, the uterus removes this extra layer through the vagina, in a process called menstrual flow, which lasts 5 days average.
Echinoderms, they are among the most common invertebrate animals in the marine environment of virtually any part of the world, among them we can find species such as sea cucumber , salmon and cod fish, they have chamois cloth like outer layer, then we have the Crinoids, another example of marine species with feather, popularly they are called sea lilies and feathery stars, they have a solid calcite skeleton; they were so abundant in the paleozoic seas that their remains formed large limestone thicknesses.
The hips ball and socket joint is much larger than the shoulders. its also protected by more muscle.
<span>Homologous chromosomes exchange DNA during meiosis in a process called crossing-over. Crossing-over sometimes involves an unequal swapping of DNA. Basically one chromosome in the pair gets extra DNA.</span>
Adenosine triphosphate (ATP) is the most important biological molecule that provides chemical energy.
